Investment in RPMG (Details) - Renewable Fuels Marketing Group (RPMG) - USD ($)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Schedule of Equity Method Investments [Line Items]
Current assets	$ 181,920,147	$ 165,666,359
Other assets	876,852	1,068,488
Current liabilities	152,492,824	135,448,249
Long-term liabilities	14,000	31,000
Members' equity	30,290,175	31,255,598
Revenue	3,244,543,605	3,070,802,183
Net income	$ 1,677,577	$ 2,099,285